Spray head



April 1, 1930. G. A. MUELLER SPRAY HEAD Filed April 21, 1927 Patented Apr. 1, 1930 UNITED "STATES PATENT OFFICE GODFREY MUELLER, OF POINT PLACE, OHIO, ASSIGNOR TO THE DE V'ILBISS 00]!!- Pm, OF TOLEDO, OHIO, A CORPORATION OF OHIO SPRAY 111mb Application filed April 21, 1927. Serial No. 185,384.

This invention relates to spraying equipment, particularly to spray-heads for airbrushes or spray-guns used for spraying surface coating materials.

It is common to make provision in such spray-heads for the discharge of supplemental streams of air against opposite sidesof the main material laden stream discharging from the spray-head to effecta flattening of said latter stream and produce what is commonly called a fan spray.

The object of this invention is to improve on spray-heads of this character by the provision of simple and efficient means for varying the angle of discharge of the siipplemental or flattening air streams with respect to the axis of discharge of the main stream or the cross-sectional size of such supplemental air streams, so that the effective pressure of discharge of the supplemental streams against the main stream may be varied within predetermined limits to produce a greater or'less flattening of the main stream, either by varying the angle of discharge of the supplemental streams or-the cross-sectional area thereof.

The invention is fully described in the following specification, and one embodiment thereof illustrated in the accompanying drawings, in which,

Figure 1 is a side elevation of thesprayhead embodying the invention with a part in central longitudinal section. Fig. 2 is a front end view thereof. Fig.3 is across-section on the line 3-3 in Fig. 1, and Fig. 4 is a view similar to Fig. 2 of a modified form of the invention.

Referring to the drawings, 1 designates the portion of a spray-gun body to which the spray-head is attached and which, w th the spray-head, in the present instance, may be considered as the spray-head unit, inasmuch as it is detachable as a unit from the spraygun body proper. "The assembled connection with a spray-gun body of such unit equipped with a different. construction of spray-head is illustrated in U. S. Letters Patent No. 1,613,588, dated Jan. 4, 1927.

The body member 1 is provided at its forward end with an enlargement 2, which is externally threaded, in the present instance, to permit the engagement therewith of a union nut 3.- The forward end of the enlargement 2 is provided with an externally threaded nipple extension 4 concentric to theaxis of said enlargement and having a bore -5 extending axially therethrough back into the'imember 1 and thence laterally through a nipple .6 adapted-to be connected to a source of'supply of the material to be sprayed.

, The inner or material discharge nozzle 7 of the spray-head, in the present instance, is of substantially conical form with its small end terminating in a restricted discharge orifice and with its rear end seating against the 6 nipple or forward extension 4 of the body member 1 with its bore in register with the bore 5 of said member. I 8 designates the control valve for the discharge orifice of the nozzle 7. The nozzle 7 is held, in the present instance, to its seat against the member 1 by a union nut 9, which threads onto the extension 4 and has shouldered .engagement with an external flange on the rear end of the nozzle. 7 v

The outer or air discharge nozzle 10 of the spray-head is mounted over the nozzle 7 with its restricted air discharge orifice'll encircling the discharge end of the inner nozzle 7 and cooperating therewith to form a thin an- .nular air discharge space so that the air discharging from the nozzle 10 completely and uniformly envelops the stream of material discharging from the nozzle 7, as well understood in the art. The nozzle 7 has an external conical surface on which the outer nozzle 10 seats, and which cooperates there with to center the air discharge orifice 11 with respect to the discharge endof thenoz-v zle 7. The rear end of the nozzle 10 ischamthe outlet orifice 11 thereof. Air under pressure is supplied to the rear chambered end of the nozzle 10 through a passage '13 in the body member 1 and this passage is adapted to have communication with a source of air pressure supply through the gun body proper, as well understood in the art.

The nozzle 10 is provided with a plurality of sets of supplemental discharge passages with each set comprising a pair of such passages disposed at diametrically opposite sides of the nozzle axis and arranged to direct their air discharge in converging relation in advance of the nozzle discharge orifice so as to meet at a point on the axial line of dis charge of the spray-head. These sets of supplemental air discharge passages, in the present instance, are three in number and designated 14, 15 and 16, and each set has its angle of discharge with respect to the axial line of the spray-head different from that of the other sets. For instance, the passages 14, 15 and 16 are arranged to have their respective lines of air discharge meet at successively varying or more remotely spaced distances from the discharge end of the nozzle, as indicated by the dotted lines in Fig. 1. The inner ends of the supplemental air passages terminate in the conical'seating surface of the nozzle 10 and the passages of any set may be placed in communication with either pair of oppositely disposed grooves 12 in the nozzle 7 while the inner ends of the other supplemental air passages are disposed at points between the grooves so that they are closed by the conical seating surface of the inner nozzle. The arrangement of the inner ends of the supplemental air passages is such that they may all be placed at points intermediate the grooves 12 so that all are closed, or the passages of any set may be placed in register with either the vertically or horizontally spaced grooves of the inner nozzle, so that the main spray stream may be flattened in either a horizontal or vertical plane. It is thus evident that all of the supplemental air passages may be closed to the source of air supply or any set may be placed in communication with such supply to suit the spraying conditions desired.

In Fig. 4 the same purpose is accomplished by making the supplemental discharge orifices 14, 15 and 16 of various cross-sectional sizes without varying the angles of discharge thereof relative to the main stream. In this figure the cooperating orifices are designated 14, 15 and 16 and are shown as being of differing cross-sectional sizes. It is apparent that the larger the size of orifices, the angle of'discharge with respect to the nozzle axis being the same, the less will be the flattening effect on the main stream.

I wish it understood that my invention is not limited to any s ecific construction, arrangement or form 0 the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A spray-head having inner and outer nozzles for discharging liquid and air respectively, said outer nozzle having a plurality of sets of opposed supplemental air discharge passages adapted to be selectively placed in register with a source of air pressure supply, with the passages of the different sets relatively angled to discharge their air streams against the main stream at different points therealong to effect a flattening of such stream.

2. A s ray-head having inner and outer nozzles or discharging liquid and an respectively, the outer nozzle being rotatable on the inner nozzle and having a plurality of sets of supplemental air passages for discharging streams of air inopposed relat on against the main stream, said passages being adapted to be placed in selective c0mmun1cation with a source of air pressure supply by a relative turning of the nozzles and each set having an angle of discharge with respect to the axis of the main stream which is different from the other sets.

3. A spray-head having an inner material discharge nozzle, and an outer air discharge nozzle having a conical seat on the inner nozle and being rotatable relative thereto, said nozzles having provision for the passage of air therebetween past the conical seating surfaces, said outer nozzle having a plurality of sets of supplemental air' discharge passages adapted to be selectively placed in communication with a source of air pressure supply or all closed to such supply by a turning of the outer nozzle on the inner nozzle and each set adapted to direct its air discharge against the main stream at a different point thereon than the other supplemental passages.

4. A spray-headhaving an inner material discharge nozzle, and an outer air discharge nozzle having a conical seat on the inner nozzle and being rotatable relative thereto, said nozzles having provision for the passage of air therebetween past the conical seatin surfaces, said outer nozzle having a plurality of sets of supplemental air discharge passages adapted to be selectivel placed in communication with a source air ressure supply or all closed to such supply By a turning of the outer nozzle on the inner nozzle and each set adapted to direct its air discharge against the main stream at a difierent angle and a different pressure than the other supplemental passages.

In testimony whereof I have hereunto signed my name to this specification.

GODFREY A. MUELLER. 

